Materials for electronic devices

ABSTRACT

The present invention relates to an electronic device comprising one or more compounds of a formula (I) or (II). Furthermore, the invention encompasses the use of a compound of the formula (I) or (II) in an electronic device, and the provision of certain compounds of the formula (I) or (II).

RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. §371)of PCT/EP2012/001156, filed Mar. 15, 2012, which claims benefit ofEuropean Application No. 11003106.9, filed Apr. 13, 2011, which isincorporated by reference herein.

The present invention relates to an electronic device comprising one ormore compounds of a formula (I) or (II) defined below. Furthermore, theinvention encompasses the use of a compound of the formula (I) or (II)in an electronic device, and the provision of certain compounds of theformula (I) or (II) defined below.

The development of novel functional compounds for use in electronicdevices is currently the subject of intense research. The aim here isthe development and investigation of compounds which have hitherto notyet been employed in electronic devices, and the development ofcompounds which facilitate an improved property profile of the devices.

The term electronic device in accordance with the present invention istaken to mean, inter alia, organic integrated circuits (OSCs), organicfield-effect transistors (OLETs), organic thin-film transistors (OTFTs),organic light-emitting transistors (OLETs), organic solar cells (OSCs),organic optical detectors, organic photoreceptors, organic field-quenchdevices (OFQDs), organic light-emitting electrochemical cells (OLECs),organic laser diodes (O-lasers) and organic electroluminescent devices(OLEDs).

The structure of organic electroluminescent devices (OLEDs) in which thecompounds of the formula (I) or (II) can preferably be employed asfunctional materials is known to the person skilled in the art and isdescribed, inter alia, in U.S. Pat. No. 4,539,507, U.S. Pat. No.5,151,629, EP 0676461 and WO 1998/27136.

Further improvements are still necessary with respect to the performancedata of the organic electroluminescent devices, in particular with aview to broad commercial use. Of particular importance in thisconnection are the lifetime, the efficiency and the operating voltage ofthe organic electroluminescent devices and the colour values achieved.In particular in the case of blue-emitting electroluminescent devices,there is potential for improvement with respect to the lifetime of thedevices.

In addition, it is desirable for the compounds for use as organicsemiconductor materials to have high thermal stability and a highglass-transition temperature and to be sublimable without decomposition.

In this connection, there is, inter alia, a demand for alternativematrix materials for use in electronic devices. In particular, there isa demand for matrix materials for phosphorescent emitters whichsimultaneously result in good efficiency, a long lifetime and a lowoperating voltage. It is precisely the properties of the matrixmaterials that are frequently limiting for the lifetime and efficiencyof the organic electroluminescent device.

In accordance with the prior art, carbazole derivatives, for examplebis(carbazolyl)biphenyl, are frequently used as matrix materials. Thereis still potential for improvement here, in particular with respect tothe lifetime and glass-transition temperature of the materials.Furthermore, there is a need for improvement with respect to theoperating voltage of the electronic devices comprising the materials inquestion.

Furthermore, ketones (WO 2004/093207), phosphine oxides, sulfones (WO2005/003253) and triazine compounds, such as triazinylspirobifluorene(cf. the applications WO 2005/053055 and WO 2010/015306), are used asmatrix materials for phosphorescent emitters. There is still potentialfor improvement here, in particular with respect to the efficiency andcompatibility with metal complexes which contain ketoketonate ligands,for example acetylacetonate.

Furthermore, metal complexes, for example BAlq or zinc(II)bis[2-(2-benzothiazole)phenolate], are used as matrix materials forphosphorescent emitters. There is still a need for improvement here, inparticular with respect to the operating voltage and chemical stability.Purely organic compounds are frequently more stable than these metalcomplexes. Thus, some of these metal complexes are sensitive tohydrolysis, which makes handling of the complexes more difficult.

Also of particular interest is the provision of alternative materials asmatrix components of mixed-matrix systems. A mixed-matrix system in thesense of this application is taken to mean a system in which two or moredifferent matrix compounds are used mixed together with one (or more)dopant compounds as the emitting layer. These systems are, inparticular, of interest in the case of phosphorescent organicelectroluminescent devices. For more detailed information, reference ismade to the application WO 2010/108579. Compounds known from the priorart which may be mentioned as matrix components in mixed-matrix systemsare, inter alia, CBP (biscarbazolylbiphenyl) and TCTA(triscarbazolyltriphenylamine). However, there continues to be a demandfor alternative compounds for use as matrix components in mixed-matrixsystems. In particular, there is a demand for compounds which effect animprovement in the operating voltage, the power efficiency and thelifetime of the electronic devices.

Furthermore, there is a demand for alternative hole-transport materialsfor use in electronic devices. In the case of hole-transport materialsin accordance with the prior art, the voltage generally increases withthe layer thickness of the hole-transport layer. In practice, a greaterlayer thickness of the hole-transport layer would frequently bedesirable, but this often has the consequence of a higher operatingvoltage and worse performance data. In this connection, there is ademand for novel hole-transport materials which have high charge-carriermobility, enabling thicker hole-transport layers to be achieved withonly a slight increase in the operating voltage.

The applications WO 2010/136109 and WO 2011/000455 discloseindenocarbazole and indolocarbazole derivatives having different linkinggeometry of the indene or indole and carbazole units. The compounds aresuitable for use as functional materials in organic electroluminescentdevices, in particular as matrix materials for phosphorescent emittersand as electron-transport materials. However, there continues to be ademand for alternative compounds, in particular those by means of whicha reduction in the operating voltage, an increase in the powerefficiency and an increase in the lifetime can be achieved.

In the course of the present invention, it has been found that compoundsof the formula (I) or (II) indicated below are highly suitable for usein electronic devices.

The present invention thus relates to an electronic device, comprisinganode, cathode and at least one organic layer, where the organic layercomprises at least one compound of the formula (I) or (II)

where:

-   Y is selected on each occurrence, identically or differently, from    BR⁰, C(R¹)₂, Si(R¹)₂, NR⁰, PR⁰, P(═O)R⁰, O, S, S═O and S(═O)₂;-   Q, Z are on each occurrence, identically or differently, CR¹ or N;-   L is selected from C═O, C═NR¹, Si(R¹)₂, NR¹, P(═O)(R¹), O, S, SO,    SO₂, alkylene groups having 1 to 20 C atoms or alkynylene or    alkynylene groups having 2 to 20 C atoms, where one or more CH₂    groups in the said groups may be replaced by Si(R¹)₂, O, S, C═O,    C═NR¹, C(═O)O, (C═O)NR¹, NR¹, P(═O)(R¹), SO or SO₂ and where one or    more H atoms in the said groups may be replaced by D, F, Cl, Br, I,    CN or NO₂, and aromatic or heteroaromatic ring systems having 5 to    60 aromatic ring atoms, which may in each case be substituted by one    or more radicals R¹, and any desired combinations of 1, 2, 3, 4 or 5    identical or different groups selected from the above-mentioned    groups; or L is a single bond, where p in this case is equal to 2;-   R⁰ is on each occurrence, identically or differently, an aromatic or    heteroaromatic ring system having 5 to 60 aromatic ring atoms, which    may be substituted by one or more radicals R², or an aralkyl group    or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may    be substituted by one or more radicals R²;-   R¹ is on each occurrence, identically or differently, H, D, F, Cl,    Br, I, B(OR²)₂, CHO, C(═O)R², CR²═C(R²)₂, CN, C(═O)OR², C(═O)N(R²)₂,    Si(R²)₃, N(R²)₂, NO₂, P(═O)(R²)₂, OSO₂R², OR², S(═O)R², S(═O)₂R², a    straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C    atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group    having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20    C atoms, where the above-mentioned groups may each be substituted by    one or more radicals R² and where one or more CH₂ groups in the    above-mentioned groups may be replaced by —R²C═CR²—, —C≡C—, Si(R²)₂,    Ge(R²)₂, Sn(R²)₂, C═O, C═S, C═Se, C═NR², —C(═O)O—, —C(═O)NR²—, NR²,    P(═O)(R²), —O—, —S—, SO or SO₂ and where one or more H atoms in the    above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or    NO₂, or an aromatic or heteroaromatic ring system having 5 to 60    aromatic ring atoms, which may in each case be substituted by one or    more radicals R², or an aryloxy, heteroaryloxy, aralkyl or    heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be    substituted by one or more radicals R², where two or more radicals    R¹ may be linked to one another and may form a ring or a ring    system;-   R² is on each occurrence, identically or differently, H, D, F, Cl,    Br, I, B(OR³)₂, CHO, C(═O)R³, CR³═C(R³)₂, CN, C(═O)OR³, C(═O)N(R³)₂,    Si(R³)₃, N(R³)₂, NO₂, P(═O)(R³)₂, OSO₂R³, OR³, S(═O)R³, S(═O)₂R³, a    straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C    atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group    having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20    C atoms, where the above-mentioned groups may each be substituted by    one or more radicals R³ and where one or more CH₂ groups in the    above-mentioned groups may be replaced by —R³C═CR³—, —C≡C—, Si(R³)₂,    Ge(R³)₂, Sn(R³)₂, C═O, C═S, C═Se, C═NR³, —C(═O)O—, —C(═O)NR³—, NR³,    P(═O)(R³), —O—, —S—, SO or SO₂ and where one or more H atoms in the    above-mentioned groups may be replaced by D, F, Cl, Br, I, CN or    NO₂, or an aromatic or heteroaromatic ring system having 5 to 60    aromatic ring atoms, which may in each case be substituted by one or    more radicals R³, or an aryloxy, heteroaryloxy, aralkyl or    heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be    substituted by one or more radicals R³, where two or more radicals    R² may be linked to one another and may form a ring or a ring    system;-   R³ is on each occurrence, identically or differently, H, D, F or an    aliphatic, aromatic and/or heteroaromatic organic radical having 1    to 20 C atoms, in which, in addition, one or more H atoms may be    replaced by D or F; two or more substituents R³ here may also be    linked to one another and form a ring or a ring system;-   n is on each occurrence, identically or differently, 0 or 1, where,    in the case n=0, the group in brackets is not present and optionally    groups R¹ are instead bonded to the central benzene ring;-   p is equal to 2, 3, 4, 5 or 6; and    where the group Y and the nitrogen atom at any desired adjacent    positions may be bonded to the aromatic six-membered ring;    where, in the formulae (I) and (II), in each case no or 1, 2 or 3    carbon atoms which are constituents of the central aromatic    six-membered ring may be replaced by N if the sum of the indices n    is equal to 0, and where, in the formulae (I) and (II), in each case    no or 1 or 2 carbon atoms which are constituents of the central    aromatic six-membered ring may be replaced by N if the sum of the    indices n is equal to 1, and    where, in formula (II), the moieties in square brackets with index p    which are bonded to L may be identical or different; and    where, in formula (II), the group L may be bonded at any desired    position of the moiety in square brackets with index p.

An aryl group in the sense of this invention contains 6 to 60 aromaticring atoms; a heteroaryl group in the sense of this invention contains 1to 60 C atoms at least one heteroatom, with the proviso that the sum ofC atoms and heteratoms is at least 5. The heteroatoms are preferablyselected from N, O and/or S.

An aryl group or heteroaryl group here is taken to mean either a simplearomatic ring, i.e. benzene, or a simple heteroaromatic ring, forexample pyridine, pyrimidine or thiophene, or a condensed (annellated)aromatic or heteroaromatic polycycle, for example naphthalene,phenanthrene, quinoline or carbazole. A condensed (annellated) aromaticor heteroaromatic polycycle in the sense of the present applicationconsists of two or more simple aromatic or heteroaromatic ringscondensed with one another.

An aryl or heteroaryl group, which may in each case be substituted bythe above-mentioned radicals and which may be linked to the aromatic orheteroaromatic ring system via any desired positions, is taken to mean,in particular, groups derived from benzene, naphthalene, anthracene,phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene,benzanthracene, benzophenanthrene, tetracene, pentacene, benzopyrene,furan, benzofuran, isobenzofuran, dibenzofuran, thiophene,benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole,isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine,phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline,benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole,imidazole, benzimidazole, naphthimidazole, phenanthrimidazole,pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole,benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole,1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine,pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine,naphthyridine, azacarbazole, benzocarboline, phenanthroline,1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole,1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole,1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine,1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine,1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine andbenzothiadiazole.

An aralkyl group in the sense of this invention is an alkyl group whichis substituted by an aryl group, where the term aryl group is to beunderstood as defined above and the alkyl group has 1 to 20 C atoms,where individual H atoms and/or CH₂ groups in the alkyl group may alsobe replaced by the groups mentioned above under the definition of R¹ andR² and where the alkyl group represents the group which is bonded to theremainder of the compound. Correspondingly, a heteroaralkyl grouprepresents an alkyl group which is substituted by a heteroaryl group,where the term heteroaryl group is to be understood as defined above andthe alkyl group has 1 to 20 C atoms, where individual H atoms and/or CH₂groups in the alkyl group may also be replaced by the groups mentionedabove under the definition of R¹ and R² and where the alkyl grouprepresents the group which is bonded to the remainder of the compound.

An aromatic ring system in the sense of this invention contains 6 to 60C atoms in the ring system. A heteroaromatic ring system in the sense ofthis invention contains 5 to 60 aromatic ring atoms, at least one ofwhich is a heteroatom. The heteroatoms are preferably selected from N, Oand/or S. An aromatic or heteroaromatic ring system in the sense of thisinvention is intended to be taken to mean a system which does notnecessarily contain only aryl or heteroaryl groups, but instead inwhich, in addition, a plurality of aryl or heteroaryl groups may beconnected by a non-aromatic unit (preferably less than 10% of the atomsother than H), such as, for example, an sp³-hybridised C, Si, N or Oatom, an sp²-hybridised C or N atom or an sp-hybridised C atom. Thus,for example, systems such as 9,9′-spirobifluorene, 9,9′-diarylfluorene,triarylamine, diaryl ether, stilbene, etc., are also intended to betaken to be aromatic ring systems in the sense of this invention, as aresystems in which two or more aryl groups are connected, for example, bya linear or cyclic alkyl, alkenyl or alkynyl group or by a silyl group.Furthermore, systems in which two or more aryl or heteroaryl groups arelinked to one another via single bonds are also taken to be aromatic orheteroaromatic ring systems in the sense of this invention, such as, forexample, systems such as biphenyl, terphenyl or diphenyltriazine.

An aromatic or heteroaromatic ring system having 5-60 aromatic ringatoms, which may in each case also be substituted by radicals as definedabove and which may be linked to the aromatic or heteroaromatic groupvia any desired positions, is taken to mean, in particular, groupsderived from benzene, naphthalene, anthracene, benzanthracene,phenanthrene, benzophenanthrene, pyrene, chrysene, perylene,fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl,biphenylene, terphenyl, terphenylene, quaterphenyl, fluorene,spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene,cis- or trans-indenofluorene, truxene, isotruxene, spirotruxene,spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran,thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole,indole, isoindole, carbazole, indolocarbazole, indenocarbazole,pyridine, quinoline, isoquinoline, acridine, phenanthridine,benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline,phenothiazine, phenoxazine, pyrazole, indazole, imidazole,benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole,pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole,naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole,1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine,benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene,2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene,4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine,phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline,phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole,1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole,1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole,1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine,tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine,purine, pteridine, indolizine and benzothiadiazole, or combinations ofthese groups.

For the purposes of the present invention, a straight-chain alkyl grouphaving 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, inwhich, in addition, individual H atoms or CH₂ groups may be substitutedby the groups mentioned above under the definition of the radicals, ispreferably taken to mean the radicals methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl,cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl,cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl,pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl,pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl,octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl oroctynyl. An alkoxy or thioalkyl group having 1 to 40 C atoms ispreferably taken to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy,i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, s-pentoxy,2-methylbutoxy, n-hexoxy, cyclohexyloxy, n-heptoxy, cycloheptyloxy,n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy,2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio,i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio,n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio,cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio,trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio,ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio,hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio,octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio,pentynylthio, hexynylthio, heptynylthio or octynylthio.

The formulation that two or more radicals may form a ring with oneanother is, the purposes of the present description, intended to betaken to mean, inter alia, that the two radicals are linked to oneanother by a chemical bond. This is illustrated by the following scheme:

Furthermore, however, the above-mentioned formulation is also intendedto be taken to mean that, in the case where one of the two radicalsrepresents hydrogen, the second radical is bonded at the position towhich the hydrogen atom was bonded, with formation of a ring. This isintended to be illustrated by the following scheme:

Furthermore, it should be emphasised that the bonds starting from N andY drawn into the central benzene ring may emanate from any desired freeposition of the benzene. However, these must be adjacent positions, asindicated above in the definition of the compounds according to theinvention.

It is not intended to be derived from the type of depiction in formula(I) and formula (II) that N must be bonded to the benzene ring above Y.The spatial arrangement of the indole derivative with the bridge Y cantherefore be selected freely within the scope of the invention, so longas N and the group Y are bonded in adjacent positions.

Preferred embodiments for the bonding positions of Y and N are revealedby the preferred structures of compounds of the formula (I) or (II)depicted in a following section.

In accordance with the invention, the group L in compounds of theformula (II) can be bonded at any desired position of the moiety insquare brackets with index p. The bonding preferably takes place toidentical positions, i.e. symmetrically. The bonding furthermorepreferably takes place via the positions marked with a circle below inthe following formula (II), where, in the case of bonding via thecentral benzene ring, a maximum of one of the two indices n may be equalto 1.

Alternatively, bonding of L may also take place via a group Y.

Preferred embodiments of formula (II) thus conform to the formulae(II-A) to (II-C)

where, in formula (II-A), the group Z to which the group L is bondedstands for a carbon atom.

According to a further preferred embodiment, the moieties in squarebrackets with index p which are bonded to L in formula (II) are selectedidentically, i.e. the compound is symmetrical.

Furthermore, the index p, which indicates the number of moieties bondedto L, is preferably equal to 2 or 3 and particularly preferably equal to2.

According to a preferred embodiment, the sum of the values for n informula (I) is equal to 0 or 1, it is particularly preferably equal to0. According to a preferred embodiment, the sum of the values for n perunit in square brackets with index p for formula (II) is equal to 0 or1, particularly preferably equal to 0.

For the group Z, this is generally preferably equal to CR¹. Furthermorepreferably, not more than 2 adjacent groups Z are equal to N.Furthermore preferably, 0, 1, 2 or 3, particularly preferably 0, 1 or 2,and very particularly preferably 0 or 1, Z per aromatic ring is equal toN.

It is furthermore preferred for the group Q to be equal to CR¹.

For the group Y, this is preferably selected on each occurrence,identically or differently, from C(R¹)₂, NR⁰, O and S, particularlypreferably from C(R¹)₂ and NR⁰ and very particularly preferably fromC(R¹)₂.

L is preferably selected from a single bond, where in this case p=2.

L is likewise preferably selected from C═O, NR¹, O or S, where in thesecases p=2, or from alkylene groups having 1 to 10 C atoms, alkenylenegroups having 2 to 10 C atoms, where one or more CH₂ groups in the saidgroups may be replaced by C═O, NR¹, P(═O)(R¹), O or S, or from aryleneor heteroarylene groups having 5 to 20 aromatic ring atoms, which may besubstituted by one or more radicals R¹. The index p in these cases ispreferably equal to 2, but may also be larger, for example 3.

L is likewise preferably a divalent aromatic or heteroaromatic ringsystem of the formula (L-1)*

E

_(i)

Ar¹

_(k)

E

_(i)

Ar¹

_(l)

E

_(i)*   formula (L-1)where p in this case is equal to 2 and where furthermore:

-   Ar¹ is on each occurrence, identically or differently, an aryl or    heteroaryl group having 5 to 20 aromatic ring atoms, which may in    each case be substituted by one or more radicals R¹;-   E is on each occurrence, identically or differently, a single bond,    C═O, NAr¹, P(═O)(R¹), O, S, SO or SO₂;-   i is on each occurrence, identically or differently, 0 or 1;-   k, l are on each occurrence, identically or differently, 0, 1, 2 or    3, where the sum of the values of k and l is greater than 0; and    where furthermore the groups Ar¹ may be connected to one another via    one or more divalent groups T, where-   T is selected on each occurrence, identically or differently, from a    single bond, BR¹, C(R¹)₂, C═O, C═S, C═NR¹, C═C(R¹)₂, CR¹═CR¹,    Si(R¹)₂, NR¹, PR¹, P(═O)R¹, O, S, S═O and S(═O)₂; and    the symbols * mark bonds from the group L to the remainder of the    compound.    L is particularly preferably a single bond or an arylene or    heteroarylene group having 5 to 18 aromatic ring atoms, which may be    substituted by one or more radicals R¹, or a divalent aromatic or    heteroaromatic ring system of the formula (L-1), where the index p    is equal to 2 and where, restricting the definitions indicated above    for formula (L-1),-   E is on each occurrence, identically or differently, a single bond,    C═O, NAr¹, O or S;-   k, l is on each occurrence, identically or differently, 0 or 1,    where the sum of the values of k and l is greater than 0; and-   T is selected on each occurrence, identically or differently, from a    single bond, C(R¹)₂, C═O, NR¹, O and S.

Furthermore preferably,

-   R⁰ is on each occurrence, identically or differently, an aromatic or    heteroaromatic ring system having 5 to 30 aromatic ring atoms, which    may be substituted by one or more radicals R².

Particularly preferably,

-   R⁰ is on each occurrence, identically or differently, an aryl or    heteroaryl group having 5 to 20 aromatic ring atoms, which may be    substituted by one or more radicals R².

Very particularly preferably,

-   R⁰ is selected on each occurrence, identically or differently, from    phenyl, naphthyl, pyridyl, pyrimidyl, pyrazinyl or triazinyl, which    may be substituted by one or more radicals R².

Preferably,

-   R¹ is selected on each occurrence, identically or differently, from    H, D, F, CN, Si(R²)₃, N(R²)₂ or a straight-chain alkyl or alkoxy    group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy    group having 3 to 20 C atoms, where the above-mentioned groups may    each be substituted by one or more radicals R² and where one or more    CH₂ groups in the above-mentioned groups may be replaced by —C≡C—,    —R²C═CR²—, Si(R²)₂, C═O, C═NR², —NR²—, —O—, —S—, —C(═O)O— or    —C(═O)NR²—, or an aromatic or heteroaromatic ring system having 5 to    20 aromatic ring atoms, which may in each case be substituted by one    or more radicals R², where two or more radicals R¹ may be linked to    one another and may form a ring or a ring system.

Particularly preferably,

-   R¹ is selected on each occurrence, identically or differently, from    H, D, F, N(R²)₂, a straight-chain alkyl group having 1 to 8 C atoms    or a branched or cyclic alkyl group having 3 to 8 C atoms, where the    above-mentioned groups may each be substituted by one or more    radicals R² and where one or more CH₂ groups in the above-mentioned    groups may be replaced by —R²C═CR²—, —NR²—, —O— or —S—, or an aryl    or heteroaryl group having 5 to 20 aromatic ring atoms, which may in    each case be substituted by one or more radicals R².

Preferably,

-   R² is selected on each occurrence, identically or differently, from    H, D, F, CN, Si(R³)₃, N(R³)₂ or a straight-chain alkyl or alkoxy    group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy    group having 3 to 20 C atoms, where the above-mentioned groups may    each be substituted by one or more radicals R³ and where one or more    CH₂ groups in the above-mentioned groups may be replaced by —C≡C—,    —R³C═CR³—, Si(R³)₂, C═O, C═NR³, —NR³—, —O—, —S—, —C(═O)O— or    —C(═O)NR³—, or an aromatic or heteroaromatic ring system having 5 to    20 aromatic ring atoms, which may in each case be substituted by one    or more radicals R³, where two or more radicals R² may be linked to    one another and may form a ring or a ring system.

Particularly preferably,

-   R² is selected on each occurrence, identically or differently, from    H, D, F, N(R³)₂, a straight-chain alkyl group having 1 to 8 C atoms    or a branched or cyclic alkyl group having 3 to 8 C atoms, where the    above-mentioned groups may each be substituted by one or more    radicals R³ and where one or more CH₂ groups in the above-mentioned    groups may be replaced by —R³C═CR³—, —NR³—, —O— or —S—, or an aryl    or heteroaryl group having 5 to 20 aromatic ring atoms, which may in    each case be substituted by one or more radicals R³.

It is furthermore preferred for the compounds according to the inventionto carry, as substituent R¹, at least one group selected from groupsR¹-I, R¹-II and R¹-III, for which:

-   R¹-I is a heteroaryl group having 5 to 20 aromatic ring atoms or a    keto group or a phosphorus oxide group or a sulfur oxide group, each    of which is bonded directly or via one or more divalent aryl or    heteroaryl groups and which may be substituted by one or more    radicals R²;-   R¹-II is an aromatic or heteroaromatic ring system having 5 to 24    aromatic ring atoms, which may be substituted by one or more    radicals R², and-   R¹-III is an arylamine group, which may be substituted by one or    more radicals R².

A keto group which is bonded directly or via one or more divalent arylgroups and which may be substituted by a radical R² is for the purposesof the present invention taken to mean a group of the following formula

where the dashed bond represents the bonding site of the keto group,

-   q can be equal to 0, 1, 2, 3, 4 or 5,-   Ar² represents on each occurrence, identically or differently, an    aryl or heteroaryl group having 5 to 20 aromatic ring atoms, which    may be substituted by one or more radicals R², where the groups Ar²    may be connected to one another via one or more groups U; and-   U is selected on each occurrence, identically or differently, from a    single bond, BR², C(R²)₂, C═O, C═S, C═NR², C═C(R²)₂, CR²═CR²,    Si(R²)₂, NR², PR², P(═O)R², O, S, S═O and S(═O)₂; and-   R² is as defined above.

A phosphorus oxide group which is bonded directly or via one or moredivalent aryl groups and which may be substituted by a radical R² is forthe purposes of the present invention taken to mean a group of thefollowing formula

where the dashed bond represents the bonding site of the phosphorusoxide group and R², q and Ar² are as defined above, where the groups Ar²may be connected to one another via one or more groups U, as definedabove.

A sulfur oxide group which is bonded directly or via one or moredivalent aryl groups and which may be substituted by a radical R² is forthe purposes of the present invention taken to mean a group of thefollowing formula

where the dashed bond represents the bonding site of the sulfur oxidegroup,a can be equal to 1 or 2,and R², q and Ar² are as defined above, where the groups Ar² may beconnected to one another via one or more groups U, as defined above.

The above-mentioned groups R¹-I preferably represent groups of thefollowing formulaHetAr¹

Ar²

_(q)*where the symbol * marks the bond to the remainder of the compound andfurthermoreq and Ar² are as defined above, where the groups Ar² may be connected toone another via one or more groups U, as defined above; and

-   HetAr¹ represents a heteroaryl group having 5 to 20 aromatic ring    atoms, which may be substituted by one or more radicals R².

HetAr¹ is preferably selected from pyridine, pyrimidine, pyridazine,pyrazine, triazine and benzimidazole, each of which may be substitutedby one or more radicals R².

The above-mentioned groups R¹-II are preferably selected from phenyl,naphthyl, anthracenyl, phenanthrenyl, benzanthracenyl, pyrenyl,biphenyl, terphenyl and quaterphenyl, each of which may be substitutedby one or more radicals R².

The above-mentioned groups R¹-III preferably represent groups of thefollowing formula

where the symbol * marks the bond to the remainder of the compound andfurthermoreq and Ar² are as defined above, where the groups Ar² may be connected toone another via one or more groups U, as defined above.

Particularly preferred embodiments of compounds of the formula (I) arethe formulae depicted below:

where the symbols occurring are as defined above and furthermore thecompounds may be substituted by radicals R¹ at all unsubstitutedpositions.

Very particular preference is given to compounds of the formulae (I-1),(I-2) and (I-3).

Particularly preferred embodiments of compounds of the formula (II-A),(II-B) and (II-C) are the formulae depicted below:

where the symbols occurring are as defined above and the group Z towhich the group L is bonded stands for a carbon atom, and wherefurthermore the compounds may be substituted by radicals R¹ at allunsubstituted positions.

For the compounds of the formulae (II-A-1) to (II-A-7), (II-B-1) to(II-B-7) and (II-C-1) to (II-C-5), the preferred embodiments indicatedabove for the variable groups generally apply.

In particular, it is preferred for these compounds for no or 1 or 2groups Z per aromatic ring to be equal to N.

Furthermore, it is preferred for these compounds for Y to be selectedfrom C(R¹)₂, NR⁰, O and S.

It is again furthermore preferred for these compounds for L to be asingle bond or to be selected from C═O, NR¹, O, S, alkylene groupshaving 1 to 10 C atoms or alkenylene groups having 2 to 10 C atoms,where one or more CH₂ groups in the said groups may be replaced by C═O,NR¹, P(═O)(R¹), O or S, or arylene or heteroarylene groups having 5 to20 aromatic ring atoms, which may be substituted by one or more radicalsR¹, or aromatic or heteroaromatic ring systems of the formula (L-1).

Particular preference is given to compounds of the formulae (II-A-1),(II-A-2), (II-A-3), (II-B-1), (II-B-2) and (II-B-3).

Still greater preference is given to compounds of the following formulae

where R¹ and L are as defined above.

For the compounds of the formulae (I-1-a) to (I-1-c), (II-A-1-a) to(II-A-1-d), (II-B-1-a) and (II-C-1-a) to (II-C-1-d), the preferredembodiments indicated above for the variable groups generally apply.

It is especially preferred for the said compounds for them to carry, assubstituent R¹, at least one group selected from groups R¹-I to R¹-IIIdefined above.

It is again furthermore preferred for these compounds for L to be asingle bond or to be selected from C═O, NR¹, O, S, alkylene groupshaving 1 to 10 C atoms or alkenylene groups having 2 to 10 C atoms,where one or more CH₂ groups in the said groups may be replaced by C═O,NR¹, P(═O)(R¹), O or S, or arylene or heteroarylene groups having 5 to20 aromatic ring atoms, which may be substituted by one or more radicalsR¹, or aromatic or heteroaromatic ring systems of the formula (L-1).

Of the said compounds, particular preference is given to compounds ofthe formulae (I-1-a), (I-1-b), (II-A-1-b), (II-B-1-a) and (II-C-1-b).

Examples of compounds according to the invention are shown in thefollowing table:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

The invention furthermore relates to a compound of the formula (I) or(II) in which the group Q is selected equal to CR¹, where the followingcompounds are excluded:

All embodiments of compounds which have been indicated as preferredabove in connection with contents of the electronic device according tothe invention are also preferred in relation to the inventivesubject-matter of the compounds themselves.

In particular, the index p, which indicates the number of moietiesbonded to L, is preferably equal to 2 or 3 and is particularlypreferably equal to 2.

According to a preferred embodiment, the sum of the values for n informula (I) is equal to 0 or 1, it is particularly preferably equal to0. According to a preferred embodiment, the sum of the values for n perunit in square brackets with index p for formula (II) is equal to 0 or1, particularly preferably equal to 0.

For the group Z, this is generally preferably equal to CR¹. Furthermorepreferably, not more than 2 adjacent groups Z are equal to N. It isfurthermore preferred for 0, 1, 2 or 3, particularly preferably 0, 1 or2, and very particularly preferably 0 or 1, Z per aromatic ring to beequal to N.

For the group Y, this is preferably selected on each occurrence,identically or differently, from C(R¹)₂, NR⁰, O and S, particularlypreferably from C(R¹)₂ and NR⁰ and very particularly preferably fromC(R¹)₂.

The compounds according to the invention can be prepared by knownorganochemical synthetic methods. These include, for example, Ullmanncoupling, Hartwig-Buchwald coupling, Suzuki coupling and brominationsand cyclisations.

Scheme 1 below shows the synthesis of skeleton A, from which compoundsaccording to the invention can be prepared via subsequent reactions.

For the synthesis of skeleton A, firstly iodobenzene is coupled tomethyl 1H-indolo-2-carboxylate in an Ullmann reaction. The resultantcompound is then brominated by means of NBS. The reaction of theresultant compound with methylmagnesium chloride followed by aring-closure reaction under dehydrating conditions gives thecorresponding bridged indolophenyl derivative.

Scheme 2 shows the synthesis of skeleton B. It differs from thesynthesis shown in Scheme 1 merely through the fact that, instead ofiodobenzene, 1,4-diiodobenzene is employed in the Ullmann coupling withtwo equivalents of methyl 1H-indolo-2-carboxylate.

Scheme 3a shows by way of example for skeleton A various ways ofobtaining compounds of the formula (I) according to the invention byderivatisation reactions. An analogous procedure can be used forskeleton B. In the first reaction shown, a Suzuki reaction is carriedout with a monoborono-functionalised aryl derivative. In the secondreaction shown, a corresponding diarylamine is introduced as substituenton the indole by a Buchwald reaction with a diarylamine.

Scheme 3b shows by way of example how compounds of the formula (II)according to the invention can be obtained from intermediates ofskeleton A. To this end, a bis-diborono-functionalised aryl derivative,shown for the example of 4,4′-diboronobiphenyl, is employed, so that askeleton A is coupled to each of the two borono-substituted positions ofthe aryl derivative.

Furthermore, other divalent aryl groups can also be employed in theSuzuki coupling in such reactions, for example heteroaryl groups, suchas dibenzothiophene, or other aryl groups, such as benzene, fluorene orterphenyl.

Scheme 4a shows by way of example for skeleton A further ways ofobtaining compounds of the formula (I) according to the invention byderivatisation reactions. An analogous procedure can be used forskeleton B. The intermediate obtained is a skeleton C.

To this end, firstly a monobromination is carried out in order to obtainthe corresponding 5-bromoindole. An aryl group or a diarylamine issubsequently introduced as substituent at position 5 of the indole ringby means of Suzuki reaction or Buchwald reaction.

Scheme 4b shows by way of example how compounds of the formula (II)according to the invention can be obtained by an analogous route toScheme 4a through the use of bifunctional aryl derivatives in theBuchwald coupling. To this end, a bis-diborono-functionalised arylderivative, shown for the example of 1,3-diboronobenzene, is employed,to which two groups of skeleton C are coupled.

In reactions in accordance with Scheme 4b, compounds of skeleton A canalso be employed instead of compounds of skeleton C in order to obtainalternative compounds of the formula (II). Furthermore, other divalentaryl groups can also be employed in the Buchwald coupling in suchreactions, for example heteroaryl groups, such as dibenzothiophene, orother aryl groups, such as benzene, fluorene or terphenyl.

The synthetic routes described above are merely intended to serve asexamples. The person skilled in the art will be able to fall back onalternative synthetic methods for the synthesis of the compoundsaccording to the invention if it appears advantageous to him under thegiven circumstances. Furthermore, he will be able to extend and/ormodify the syntheses shown using his general expert knowledge in thearea of organic synthetic chemistry in order to prepare compoundsaccording to the invention.

The invention thus furthermore relates to a process for the preparationof a compound of the formula (I) or (II) in which the group Q isselected equal to CR¹, characterised in that it comprises at least oneorganometallic coupling reaction between an indole derivative and ahalogen-substituted aromatic or heteroaromatic compound and at least onering-closure reaction between the indole derivative and the coupledaromatic or heteroaromatic compound.

The compounds of the formula (I) or (II) described above, in particularcompounds which are substituted by reactive leaving groups, such asbromine, iodine, chlorine, boronic acid or boronic acid ester, can beused as monomers for the preparation of oligomers, dendrimers orpolymers. The oligomerisation or polymerisation here preferably takesplace via the halogen functionality or the boronic acid functionality.

The invention therefore furthermore relates to oligomers, polymers ordendrimers containing one or more compounds of the formula (I) or (II),where the bond(s) to the polymer, oligomer or dendrimer can be localisedat any desired positions in formula (I) or (II) which are substituted byR⁰ or R¹. Depending on the linking of the compound of the formula (I) or(II), the compound is a constituent of a side chain of the oligomer orpolymer or a constituent of the main chain. An oligomer in the sense ofthis invention is taken to mean a compound which is built up from atleast three monomer units. A polymer in the sense of the invention istaken to mean a compound which is built up from at least ten monomerunits. The polymers, oligomers or dendrimers according to the inventionmay be conjugated, partially conjugated or non-conjugated. The oligomersor polymers according to the invention may be linear, branched ordendritic. In the structures linked in a linear manner, the units of theformula (I) or (II) may be linked directly to one another or they may belinked to one another via a divalent group, for example via asubstituted or unsubstituted alkylene group, via a heteroatom or via adivalent aromatic or heteroaromatic group. In branched and dendriticstructures, for example, three or more units of the formula (I) or (II)may be linked via a trivalent or polyvalent group, for example via atrivalent or polyvalent aromatic or heteroaromatic group, to form abranched or dendritic oligomer or polymer.

The same preferences as described above for compounds of the formula (I)or (II) apply to the recurring units of the formula (I) or (II) inoligomers, dendrimers and polymers.

For the preparation of the oligomers or polymers, the monomers accordingto the invention are homopolymerised or copolymerised with furthermonomers. Suitable and preferred comonomers are selected from fluorenes(for example in accordance with EP 842208 or WO 2000/22026),spirobifluorenes (for example in accordance with EP 707020, EP 894107 orWO 2006/061181), para-phenylenes (for example in accordance with WO1992/18552), carbazoles (for example in accordance with WO 2004/070772or WO 2004/113468), thiophenes (for example in accordance with EP1028136), dihydrophenanthrenes (for example in accordance with WO2005/014689 or WO 2007/006383), cis- and trans-indenofluorenes (forexample in accordance with WO 2004/041901 or WO 2004/113412), ketones(for example in accordance with WO 2005/040302), phenanthrenes (forexample in accordance with WO 2005/104264 or WO 2007/017066) or also aplurality of these units. The polymers, oligomers and dendrimers usuallyalso contain further units, for example emitting (fluorescent orphosphorescent) units, such as, for example, vinyltriarylamines (forexample in accordance with WO 2007/068325) or phosphorescent metalcomplexes (for example in accordance with WO 2006/003000), and/orcharge-transport units, in particular those based on triarylamines.

The polymers, oligomers and dendrimers according to the invention haveadvantageous properties, in particular long lifetimes, high efficienciesand good colour coordinates.

The polymers and oligomers according to the invention are generallyprepared by polymerisation of one or more types of monomer, of which atleast one monomer results in recurring units of the formula (I) or (II)in the polymer. Suitable polymerisation reactions are known to theperson skilled in the art and are described in the literature.Particularly suitable and preferred polymerisation reactions whichresult in C—C or C—N links are the following:

(A) SUZUKI polymerisation;

(B) YAMAMOTO polymerisation;

(C) STILLE polymerisation; and

(D) HARTWIG-BUCHWALD polymerisation.

The way in which the polymerisation can be carried out by these methodsand the way in which the polymers can then be separated off from thereaction medium and purified is known to the person skilled in the artand is described in detail in the literature, for example in WO2003/048225, WO 2004/037887 and WO 2004/037887.

The present invention thus also relates to a process for the preparationof the polymers, oligomers and dendrimers according to the invention,which is characterised in that they are prepared by SUZUKIpolymerisation, YAMAMOTO polymerisation, STILLE polymerisation orHARTWIG-BUCHWALD polymerisation. The dendrimers according to theinvention can be prepared by processes known to the person skilled inthe art or analogously thereto. Suitable processes are described in theliterature, such as, for example, in Frechet, Jean M. J.; Hawker, CraigJ., “Hyperbranched polyphenylene and hyperbranched polyesters: newsoluble, three-dimensional, reactive polymers”, Reactive & FunctionalPolymers (1995), 26(1-3), 127-36; Janssen, H. M.; Meijer, E. W., “Thesynthesis and characterization of dendritic molecules”, MaterialsScience and Technology (1999), 20 (Synthesis of Polymers), 403-458;Tomalia, Donald A., “Dendrimer molecules”, Scientific American (1995),272(5), 62-6; WO 02/067343 A1 and WO 2005/026144 A1.

For the processing of the compounds formula (I) or (II) from liquidphase, for example by spin coating or by printing processes,formulations of the compounds are necessary. These formulations can be,for example, solutions, dispersions or mini-emulsions.

The invention therefore furthermore relates to a formulation, inparticular a solution, dispersion or mini-emulsion, comprising at leastone compound of the formula (I) or (II) or at least one polymer,oligomer or dendrimer containing at least one unit of the formula (I) or(II) and at least one solvent, preferably an organic solvent. The way inwhich solutions of this type can be prepared is known to the personskilled in the art and is described, for example, in the applications WO2002/072714 and WO 2003/019694 and the literature cited therein.Preference is given to a formulation comprising at least one compound ofthe formula (I) or (II), where the group Q is selected equal to CR¹, andat least one solvent.

The compounds of the formula (I) or (II) are suitable for use inelectronic devices, in particular in organic electroluminescent devices(OLEDs). Depending on the substitution, the compounds are preferablyemployed in certain functions and/or layers.

For example, compounds of the formula (I) or (II) which carry at leastone group R¹-I as substituent R¹, as defined above, are particularlysuitable for use as matrix material for phosphorescent dopants, aselectron-transport material or as hole-blocking material. The group R¹-Ihere preferably contains at least one electron-deficient group, such assix-membered heteroaryl ring groups containing one or more nitrogenatoms or five-membered heteroaryl ring groups containing two or morenitrogen atoms.

Furthermore, compounds of the formula (I) or (II) which carry at leastone group R¹-II and/or R¹-III as substituent R¹, as defined above, areparticularly suitable for use as hole-transport materials or for use asfluorescent dopants. The group R¹-II here preferably contains anaromatic ring system having 12 to 20 aromatic ring atoms.

The compounds of the formula (I) or (II) are preferably employed aselectron-transport material in an electron-transport layer, as matrixmaterial in an emitting layer or as hole-transport material in ahole-transport layer. If the compounds are employed as matrix materialsin an emitting layer, the emitting layer preferably comprises at leastone phosphorescent emitter compound. However, the compounds may also beemployed in other layers and/or functions, for example as fluorescentdopants in an emitting layer or as hole- or electron-blocking materials.

The invention therefore furthermore relates to the use of the compoundsof the formula (I) or (II) in electronic devices. The electronic deviceshere are preferably selected from the group consisting of organicintegrated circuits (O-ICs), organic field-effect transistors (O-FETs),organic thin-film transistors (O-TFTs), organic light-emittingtransistors (O-LETs), organic solar cells (O-SCs), organic opticaldetectors, organic photoreceptors, organic field-quench devices(O-FQDs), light-emitting electrochemical cells (LECs), organic laserdiodes (O-lasers) and particularly preferably selected from organicelectroluminescent devices (OLEDs).

The invention relates, as already mentioned above, to an electronicdevice comprising anode, cathode and at least one organic layer, wherethe organic layer comprises at least one compound of the formula (I) or(II). The electronic device here is preferably selected from theabove-mentioned devices and is particularly preferably an organicelectroluminescent device.

Apart from cathode, anode and the emitting layer, the organicelectroluminescent device may also comprise further layers. These areselected, for example, from in each case one or more hole-injectionlayers, hole-transport layers, hole-blocking layers, electron-transportlayers, electron-injection layers, electron-blocking layers,exciton-blocking layers, charge-generation layers (IDMC 2003, Taiwan;Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K. Mori, N.Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having ChargeGeneration Layer), coupling-out layers and/or organic or inorganic p/njunctions. However, it should be pointed out that each of these layersdoes not necessarily have to be present and the choice of layers isalways dependent on the compounds used and in particular also on whetherthe electroluminescent device is fluorescent or phosphorescent. Thecompounds preferably employed in the respective layers and functions areexplicitly disclosed in later sections.

It is preferred in accordance with the invention for the compound of theformula (I) or (II) to be employed in an electronic device comprisingone or more phosphorescent dopants. The compound can be used in variouslayers here, preferably in an electron-transport layer, a hole-transportlayer, a hole-injection layer or in the emitting layer. However, thecompound of the formula (I) or (II) can also be employed in accordancewith the invention in an electronic device comprising one or morefluorescent dopants and no phosphorescent dopants.

The term phosphorescent dopants typically encompasses compounds in whichthe light emission takes place by a spin-forbidden transition, forexample a transition from an excited triplet state or a state having arelatively high spin quantum number, for example a quintet state.

Suitable phosphorescent dopants are, in particular, compounds which emitlight, preferably in the visible region, on suitable excitation and inaddition contain at least one atom having an atomic number greater than20, preferably greater than 38 and less than 84, particularly preferablygreater than 56 and less than 80. The phosphorescent dopants used arepreferably compounds which contain copper, molybdenum, tungsten,rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum,silver, gold or europium, in particular compounds which contain iridium,platinum or copper.

For the purposes of the present invention, all luminescent iridium,platinum or copper complexes are regarded as phosphorescent compounds.

Examples of the phosphorescent dopants described above are revealed bythe applications WO 2000/70655, WO 2001/41512, WO 2002/02714, WO2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 2005/033244, WO2005/019373 and US 2005/0258742. In general, all phosphorescentcomplexes as used in accordance with the prior art for phosphorescentOLEDs and as are known to the person skilled in the art in the area oforganic electroluminescent devices are suitable. The person skilled inthe art will also be able to employ further phosphorescent complexeswithout inventive step in combination with the compounds according tothe invention in organic electroluminescent devices. Further examples ofsuitable phosphorescent dopants are revealed by the table following in alater section.

In a preferred embodiment of the present invention, the compounds of theformula (I) or (II) are employed as matrix material in combination withone or more dopants, preferably phosphorescent dopants. The compoundsare particularly suitable for use as matrix material if they contain oneor more groups of the formula R¹-I, such as, for example, six-memberedheteroaryl ring groups containing one or more nitrogen atoms orfive-membered heteroaryl ring groups containing two or more nitrogenatoms.

A dopant in a system comprising a matrix material and a dopant is takento mean the component whose proportion in the mixture is the smaller.Correspondingly, a matrix material is taken to mean the component whoseproportion in the mixture is the greater in a system comprising a matrixmaterial and a dopant.

The proportion of the matrix material in the emitting layer is in thiscase between 50.0 and 99.9% by vol., preferably between 80.0 and 99.5%by vol. and particularly preferably between 92.0 and 99.5% by vol. forfluorescent emitting layers and between 85.0 and 97.0% by vol. forphosphorescent emitting layers.

Correspondingly, the proportion of the dopant is between 0.1 and 50.0%by vol., preferably between 0.5 and 20.0% by vol. and particularlypreferably between 0.5 and 8.0% by vol. for fluorescent emitting layersand between 3.0 and 15.0% by vol. for phosphorescent emitting layers.

An emitting layer of an organic electroluminescent device may alsocomprise systems comprising a plurality of matrix materials(mixed-matrix systems) and/or a plurality of dopants. In this case too,the dopants are generally the materials whose proportion in the systemis the smaller and the matrix materials are the materials whoseproportion in the system is the greater. In individual cases, however,the proportion of an individual matrix material in the system may besmaller than the proportion of an individual dopant.

In a further preferred embodiment of the invention, the compounds of theformula (I) or (II) are used as a component of mixed-matrix systems. Themixed-matrix systems preferably comprise two or three different matrixmaterials, particularly preferably two different matrix materials. Oneof the two materials here is preferably a material havinghole-transporting properties and the other material is a material havingelectron-transporting properties. The two different matrix materialshere may be present in a ratio of 1:50 to 1:1, preferably 1:20 to 1:1,particularly preferably 1:10 to 1:1 and very particularly preferably 1:4to 1:1. Mixed-matrix systems are preferably employed in phosphorescentorganic electroluminescent devices.

The mixed-matrix systems may comprise one or more dopants. The dopantcompound or the dopant compounds together have, in accordance with theinvention, a proportion of 0.1 to 50.0% by vol. in the mixture as awhole and preferably a proportion of 0.5 to 20.0% by vol. in the mixtureas a whole. Correspondingly, the matrix components together have aproportion of 50.0 to 99.9% by vol. in the mixture as a whole andpreferably a proportion of 80.0 to 99.5% by vol. in the mixture as awhole.

Particularly suitable matrix materials, which can be employed incombination with the compounds according to the invention as matrixcomponents of a mixed-matrix system, are aromatic ketones, aromaticphosphine oxides or aromatic sulfoxides or sulfones, for example inaccordance with WO 2004/013080, WO 2004/093207, WO 2006/005627 or WO2010/006680, triarylamines, carbazole derivatives, for example CBP(N,N-biscarbazolylbiphenyl) or the carbazole derivatives disclosed in WO2005/039246, US 2005/0069729, JP 2004/288381, EP 1205527 or WO2008/086851, indolocarbazole derivatives, for example in accordance withWO 2007/063754 or WO 2008/056746, azacarbazole derivatives, for examplein accordance with EP 1617710, EP 1617711, EP 1731584, JP 2005/347160,bipolar matrix materials, for example in accordance with WO 2007/137725,silanes, for example in accordance with WO 2005/111172, azaboroles orboronic esters, for example in accordance with WO 2006/117052, triazinederivatives, for example in accordance with WO 2010/015306, WO2007/063754 or WO 2008/056746, zinc complexes, for example in accordancewith EP 652273 or WO 2009/062578, diazasilole or tetraazasilolederivatives, for example in accordance with WO 2010/054729,diazaphosphole derivatives, for example in accordance with WO2010/054730, or indenocarbazole derivatives, for example in accordancewith WO 10/136,109 and WO 2011/000455, or bridged carbazoles, forexample in accordance with WO 2011/088877 and WO 2011/128017.

Preferred phosphorescent dopants for use in mixed-matrix systemscomprising the compounds according to the invention are thephosphorescent dopants shown in a following table.

In a further preferred embodiment of the invention, the compounds of theformula (I) or (II) are employed as hole-transport material. Thecompounds are then preferably employed in a hole-transport layer and/orin a hole-injection layer. A hole-injection layer in the sense of thisinvention is a layer which is directly adjacent to the anode. Ahole-transport layer in the sense of this invention is a layer which islocated between the hole-injection layer and the emission layer. Thecompounds are used as hole-transport material if, in particular, theyare substituted by one or more aromatic ring systems having 12 to 20aromatic ring atoms and/or by one or more arylamino groups.

If the compound of the formula (I) or (II) is employed as hole-transportmaterial in a hole-transport layer, the compound can be employed as purematerial, i.e. in a proportion of 100%, in the hole-transport layer orit can be employed in combination with further compounds in thehole-transport layer.

In a further embodiment of the invention, the compounds of the formula(I) or (II) are employed as fluorescent dopants in an emitting layer. Inparticular, the compounds are suitable as fluorescent dopants if theyare substituted by one or more aromatic systems, preferably aromaticsystems containing 12 to 20 aromatic ring atoms. The compounds accordingto the invention are preferably used as green or blue emitters.

The proportion of the compound of the formula (I) or (II) as dopant inthe mixture of the emitting layer is in this case between 0.1 and 50.0%by vol., preferably between 0.5 and 20.0% by vol., particularlypreferably between 0.5 and 8.0% by vol. Correspondingly, the proportionof the matrix material is between 50.0 and 99.9% by vol., preferablybetween 80.0 and 99.5% by vol., particularly preferably between 92.0 and99.5% by vol.

Preferred matrix materials for use in combination with the compoundsaccording to the invention as fluorescent dopants are mentioned in oneof the following sections. They correspond to the matrix materials forfluorescent dopants that are indicated as preferred.

In a further embodiment of the invention, the compounds are employed aselectron-transport materials in an electron-transport layer of anorganic electroluminescent device. The compounds are particularlysuitable for use as electron-transport material if they contain one ormore groups of the formula R¹-I, such as, for example, six-memberedheteroaryl ring groups containing one or more, nitrogen atoms orfive-membered heteroaryl ring groups containing two or more nitrogenatoms.

The organic electroluminescent device may also comprise a plurality ofemitting layers. These emission layers in this case particularlypreferably have in total a plurality of emission maxima between 380 nmand 750 nm, resulting overall in white emission, i.e. various emittingcompounds which are able to fluoresce or phosphoresce and which emitblue or yellow or orange or red light are used in the emitting layers,where the various colours in this embodiment of the invention togethergive white light. Particular preference is given to three-layer systems,i.e. systems having three emitting layers, where one or more of theselayers comprises a compound of the formula (I) or (II) and where thethree layers exhibit blue, green and orange or red emission (for thebasic structure see, for example, WO 2005/011013). Likewise, emitterswhich have broad-band emission bands and thus exhibit white emission aresuitable for white emission in such systems. Alternatively and/oradditionally, the compounds according to the invention may also bepresent in a hole-transport layer or electron-transport layer or inanother layer in such systems.

The further functional materials preferably employed in the electronicdevices comprising one or more compounds of the formula (I) or (II) areshown below.

The compounds shown in the following table are particularly suitablephosphorescent dopants.

Preferred fluorescent dopants are selected from the class of themonostyrylamines, the distyrylamines, the tristyrylamines, thetetrastyrylamines, the styrylphosphines, the styryl ethers and thearylamines. A monostyrylamine is taken to mean a compound which containsone substituted or unsubstituted styryl group and at least one,preferably aromatic, amine. A distyrylamine is taken to mean a compoundwhich contains two substituted or unsubstituted styryl groups and atleast one, preferably aromatic, amine. A tristyrylamine is taken to meana compound which contains three substituted or unsubstituted styrylgroups and at least one, preferably aromatic, amine. A tetrastyrylamineis taken to mean a compound which contains four substituted orunsubstituted styryl groups and at least one, preferably aromatic,amine. The styryl groups are particularly preferably stilbenes, whichmay also be further substituted. Corresponding styrylphosphines andstyryl ethers are defined analogously to the amines. An arylamine oraromatic amine in the sense of this invention is taken to mean acompound which contains three substituted or unsubstituted aromatic orheteroaromatic ring systems bonded directly to the nitrogen. At leastone of these aromatic or heteroaromatic ring systems is preferably acondensed ring system, particularly preferably having at least 14aromatic ring atoms. Preferred examples thereof are aromaticanthracenamines, aromatic anthracenediamines, aromatic pyrenamines,aromatic pyrenediamines, aromatic chrysenamines or aromaticchrysenediamines. An aromatic anthracenamine is taken to mean a compoundin which one diarylamino group is bonded directly to an anthracenegroup, preferably in the 9-position. An aromatic anthracenediamine istaken to mean a compound in which two diarylamino groups are bondeddirectly to an anthracene group, preferably in the 9,10-position.Aromatic pyrenamines, pyrenediamines, chrysenamines and chrysenediaminesare defined analogously thereto, where the diarylamino groups arepreferably bonded to the pyrene in the 1-position or in the1,6-position. Further preferred fluorescent dopants are selected fromindenofluorenamines or indenofluorenediamines, for example in accordancewith WO 2006/122630, benzoindenofluorenamines orbenzoindenofluorenediamines, for example in accordance with WO2008/006449, and dibenzoindenofluorenamines ordibenzoindenofluorenediamines, for example in accordance with WO2007/140847. Examples of fluorescent dopants from the class of thestyrylamines are substituted or unsubstituted tristilbenamines or thefluorescent dopants described in WO 2006/000388, WO 2006/058737, WO2006/000389, WO 2007/065549 and WO 2007/115610. Preference isfurthermore given to the condensed hydrocarbons disclosed in WO2010/012328. Furthermore, the compounds of the formula (I) or (II) canalso be used as fluorescent dopants.

Suitable fluorescent dopants are furthermore the structures disclosed inJP 2006/001973, WO 2004/047499, WO 2006/098080, WO 2007/065678, US2005/0260442 and WO 2004/092111.

Suitable matrix materials, preferably for fluorescent dopants, arematerials from various classes of substance. Preferred matrix materialsare selected from the classes of the oligoarylenes (for example2,2′,7,7′-tetraphenylspirobifluorene in accordance with EP 676461 ordinaphthylanthracene), in particular the oligoarylenes containingcondensed aromatic groups, the oligoarylenevinylenes (for example DPVBior spiro-DPVBi in accordance with EP 676461), the polypodal metalcomplexes (for example in accordance with WO 2004/081017), thehole-conducting compounds (for example in accordance with WO2004/058911), the electron-conducting compounds, in particular ketones,phosphine oxides, sulfoxides, etc. (for example in accordance with WO2005/084081 and WO 2005/084082), the atropisomers (for example inaccordance with WO 2006/048268), the boronic acid derivatives (forexample in accordance with WO 2006/117052) or the benzanthracenes (forexample in accordance with WO 2008/145239). Preferred matrix materialsare furthermore the compounds of the formula (I) or (II). Particularlypreferred matrix materials are selected from the classes of theoligoarylenes, comprising naphthalene, anthracene, benzanthracene and/orpyrene or atropisomers of these compounds, the oligoarylenevinylenes,the ketones, the phosphine oxides and the sulfoxides. Very particularlypreferred matrix materials are selected from the classes of theoligoarylenes, comprising anthracene, benzanthracene, benzophenanthreneand/or pyrene or atropisomers of these compounds. An oligoarylene in thesense of this invention is intended to be taken to mean a compound inwhich at least three aryl or arylene groups are bonded to one another.

Suitable matrix materials, preferably for fluorescent dopants, aredisclosed, for example, in WO 2004/018587, WO 2008/006449, U.S. Pat. No.5,935,721, US 2005/0181232, JP 2000/273056, EP 681019, US 2004/0247937and US 2005/0211958.

Preferred matrix materials for phosphorescent dopants are carbazolederivatives (for example CBP, N,N-biscarbazolylbiphenyl) or compounds inaccordance with WO 2005/039246, US 2005/0069729, JP 2004/288381, EP1205527 or WO 2008/086851), triarylamines, azacarbazoles (for example inaccordance with EP 1617710, EP 1617711, EP 1731584, JP 2005/347160),indolocarbazole derivatives (for example in accordance with WO2007/063754 or WO 2008/056746), ketones (for example in accordance withWO 2004/093207 or WO 2010/006680), phosphine oxides, sulfoxides andsulfones (for example in accordance with WO 2005/003253),oligophenylenes, aromatic amines (for example in accordance with US2005/0069729), bipolar matrix materials (for example in accordance withWO 2007/137725), silanes (for example in accordance with WO2005/111172), azaboroles or boronic esters (for example in accordancewith WO 2006/117052), triazine derivatives (for example in accordancewith WO 2010/015306, WO 2007/063754 or WO 2008/056746), zinc complexes(for example in accordance with WO 2009/062578), aluminium complexes(for example BAlq), diazasilole and tetraazasilole derivatives, forexample in accordance with WO 2010/054730, indenocarbazole derivatives,for example in accordance with WO 2010/136109 and WO 2011/000455 ordiazaphospholes, for example in accordance with WO 2010/054730.

Suitable charge-transport materials, as can be used in thehole-injection or hole-transport layer or in the electron-transportlayer of the organic electroluminescent device according to theinvention, are, for example, the compounds disclosed in Y. Shirota etal., Chem. Rev. 2007, 107(4), 953-1010, or other materials as areemployed in these layers in accordance with the prior art.

The cathode preferably comprises metals having a low work function,metal alloys or multilayered structures comprising various metals, suchas, for example, alkaline-earth metals, alkali metals, main-group metalsor lanthanoids (for example Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Alsosuitable are alloys comprising an alkali metal or alkaline-earth metaland silver, for example an alloy comprising magnesium and silver. In thecase of multilayered structures, further metals which have a relativelyhigh work function, such as, for example, Ag or Al, can also be used inaddition to the said metals, in which case combinations of the metals,such as, for example, Ca/Ag, Ba/Ag, Ba/Al or Mg/Ag, are generally used.It may also be preferred to introduce a thin interlayer of a materialhaving a high dielectric constant between a metallic cathode and theorganic semiconductor. Suitable for this purpose are, for example,alkali metal fluorides or alkaline-earth metal fluorides, but also thecorresponding oxides or carbonates (for example LiF, Li₂O, BaF₂, MgO,NaF, CsF, Cs₂CO₃, etc.). Furthermore, lithium quinolinate (LiQ) can beused for this purpose. The layer thickness of this layer is preferablybetween 0.5 and 5 nm.

The anode preferably comprises materials having a high work function.The anode preferably has a work function of greater than 4.5 eV vs.vacuum. Suitable for this purpose are on the one hand metals having ahigh redox potential, such as, for example, Ag, Pt or Au. On the otherhand, metal/metal oxide electrodes (for example Al/Ni/NiO_(x),Al/PtO_(x)) may also be preferred. For some applications, at least oneof the electrodes must be transparent or partially transparent in orderto facilitate either irradiation of the organic material (organic solarcells) or the coupling-out of light (OLEDs, O-lasers). Preferred anodematerials here are conductive mixed metal oxides. Particular preferenceis given to indium tin oxide (ITO) or indium zinc oxide (IZO).Preference is furthermore given to conductive, doped organic materials,in particular conductive, doped polymers.

The device is appropriately (depending on the application) structured,provided with contacts and finally sealed, since the lifetime of thedevices according to the invention is shortened in the presence of waterand/or air.

In a preferred embodiment, the organic electroluminescent deviceaccording to the invention is characterised in that one or more layersare coated by means of a sublimation process, in which the materials areapplied by vapour deposition in vacuum sublimation units at an initialpressure of less than 10⁻⁶ mbar, preferably less than 10⁻⁶ mbar.However, it is also possible here for the initial pressure to be evenlower, for example less than 10⁻⁷ mbar.

Preference is likewise given to an organic electroluminescent device,characterised in that one or more layers are coated by means of the OVPD(organic vapour phase deposition) process or with the aid of carrier-gassublimation, in which the materials are applied at a pressure of between10⁻⁵ mbar and 1 bar. A special case of this process is the OVJP (organicvapour jet printing) process, in which the materials are applieddirectly through a nozzle and are thus structured (for example M. S.Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

Preference is furthermore given to an organic electroluminescent device,characterised in that one or more layers are produced from solution,such as, for example, by spin coating, or by means of any desiredprinting process, such as, for example, screen printing, flexographicprinting, nozzle printing or offset printing, but particularlypreferably LITI (light induced thermal imaging, thermal transferprinting) or ink-jet printing. Soluble compounds of the formula (I) or(II) are necessary for this purpose. High solubility can be achievedthrough suitable substitution of the compounds.

For the production of an organic electroluminescent device according tothe invention, it is furthermore preferred to apply one or more layersfrom solution and one or more layers by a sublimation process.

The organic electroluminescent devices comprising one or more compoundsaccording to the invention can be employed in displays, as light sourcesin lighting applications and as light sources in medical and/or cosmeticapplications (for example light therapy).

On use of the compounds of the formula (I) or (II) in an organicelectroluminescent device, one or more of the advantages mentioned belowcan be achieved:

The compounds according to the invention are very highly suitable foruse as matrix materials for phosphorescent dopants and for use aselectrontransport materials. On use of the compounds according to theinvention in these functions, good power efficiencies, low operatingvoltages and good lifetimes of the organic electroluminescent devicesare obtained.

Furthermore, the compounds according to the invention are distinguishedby high oxidation stability in solution, which has an advantageouseffect during purification and handling of the compounds and on usethereof in electronic devices.

Furthermore, the compounds according to the invention aretemperature-stable and can thus be sublimed substantially withoutdecomposition. Purification of the compounds is thus simplified, and thecompounds can be obtained in higher purity, which has a positive effecton the performance data of the electronic devices comprising thematerials. In particular, devices having longer operating lifetimes canthus be produced.

The invention is explained in greater detail by the following workingexamples, with the invention not being restricted to the scope of theexamples.

USE EXAMPLES A) Synthesis Examples

The following syntheses are carried out, unless indicated otherwise,under a protective-gas atmosphere in dried solvents. The solvents andreagents indicated are commercially available.

Example 1:11-[3-(4,6-Diphenyl-1,3,5-triazin-2-yl)phenyl]-10,10-dimethyl-10H-indolo[1,2-a]indole

1st Step:

50 g (285 mmol) of 2-methyl indole-2-carboxylate, 116.4 g (571 mmol) ofiodobenzene and 98.5 g of K₂CO₃ (712.5 mmol) are suspended in 11 oftoluene. 15.8 g (114 mmol) of CuI and 10.06 g of N,N′-dimethylenediamine(114 mmol) are added to this suspension. The reaction mixture is heatedunder reflux for 48 h. After cooling, the precipitate is filtered offvia a fluted filter. The reaction solution is subsequently partitionedbetween ethyl acetate and water, the organic phase is washed three timeswith water, dried over Na₂SO₄ and evaporated in vacuo. The black-greenoil remaining is filtered through silica gel with heptane:toluene. Theevaporated filtrate residue is subsequently recrystallised frommethanol. Yield: 57 g of 1-phenyl-1H-indole-2-methylcarboxylate (80%)

2nd Step:

57 g (227 mmol) of 1-phenyl-1H-indole-2-methylcarboxylate are initiallyintroduced in 500 ml of dimethylformamide. A solution of 40.4 g (227mmol) of NBS in 100 ml of dimethylformamide is subsequently addeddropwise at 0° C. with exclusion of light, the mixture is allowed tocome to RT and is stirred at this temperature for a further 4 h. Themixture is subsequently poured into ice-water. The precipitate isfiltered, washed with water and subsequently washed with heptane. Theproduct is washed by stirring with hot heptane and filtered off withsuction. Yield: 71.1 g, (95%)

3rd Step:

57.48 g of anhydrous cerium(III) chloride (233 mmol) is initiallyintroduced in 700 ml of dry THF. 70 g (212 mmol) of1-phenyl-3-bromo-1H-indole-2-methylcarboxylate are metered into thissolution in portions, and the mixture is stirred for 1 h. The reactionmixture is cooled, and 212 ml (636 mmol) of methylmagnesium chloridesolution (3 mol/l in THF) are added dropwise at 5° C. over the course of40 min. After one hour, the reaction mixture is carefully poured ontoice and extracted three times with dichloromethane. The combined organicphases are dried over Na₂SO₄ and evaporated. The residue isrecrystallised from toluene. Yield: 65.8 g (94%)

4th Step:

157 g of polyphosphoric acid (1.6 mol) and 104 g of methanesulfonic acid(1.1 mol) are initially introduced in 11 of CH₂Cl₂. 65 g (197 mmol) of2-(3-bromo-1-phenyl-1H-indol-2-yl)propan-2-ol in dichloromethanesolution (150 ml) are added dropwise to this solution over the course of30 min, and the mixture is stirred at 50° C. for 1 h. After this time,the reaction mixture is cooled, carefully poured onto ice and extractedthree times with dichloromethane. The combined organic phases are driedover Na₂SO₄ and evaporated. The residue is recrystallised from toluene.Yield: 52.3 g of 11-bromo-10,10-dimethyl-10H-indolo[1,2-a]indole (85%)

5th Step:

20 g (57 mmol) of 11-bromo-10,10-dimethyl-10H-indolo[1,2-a]indole, 25 g(57 mmol) of2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazineand 86 ml of a 2M sodium carbonate solution are suspended in 500 ml ofethylene glycol dimethyl ether. 1.66 g (1.43 mmol) of Pd(PPh₃)₄ areadded to this suspension. The reaction mixture is heated under refluxfor 5 h. After cooling, the precipitated solid is filtered off withsuction and washed with water and ethanol and dried. The residue isextracted with hot toluene, recrystallised from toluene and finallysublimed in a high vacuum. The purity is 99.9%. Yield: 19.5 g (59%).

Example 2:Bisbiphenyl-4-yl-[4-(11,11-dimethyl-1H-indolo[1,2-a]indol-10-yl)phenyl]amine

20 g (64 mmol) of 11-bromo-10,10-dimethyl-10H-indolo[1,2-a]indole (4thstep of Example 1), 33.5 g (64 mmol) ofbisbiphenyl-4-yl-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]amineand 96 ml of a 2M sodium carbonate solution are suspended in 500 ml ofethylene glycol dimethyl ether. 1.66 g (1.43 mmol) of Pd(PPh₃)₄ areadded to this suspension. The reaction mixture is heated under refluxfor 10 h. After cooling, the precipitated solid is filtered off withsuction, washed with water and ethanol and dried. The residue isextracted with hot toluene, recrystallised from toluene and subsequentlysublimed in a high vacuum. The purity is 99.9%. Yield: 26 g (65%).

Example 3:Bis-10,10′-[(4-4′-biphenyl)-11,11-dimethyl-1H-indolo-[1,2-a]indole

30 g (96 mmol) of 11-bromo-10,10-dimethyl-10H-indolo[1,2-a]indole (4thstep of Example 1), 11.6 g (48 mmol) of 4,4′-biphenyldiboronic acid and145 ml of a 2M sodium carbonate solution are suspended in 600 ml ofethylene glycol dimethyl ether. 2.77 g (2.4 mmol) of Pd(PPh₃)₄ are addedto this suspension. The reaction mixture is heated under reflux for 12h. After cooling, the precipitated solid is filtered off with suction,washed with water and ethanol and dried. The residue is extracted withhot toluene, recrystallised from toluene and subsequently sublimed in ahigh vacuum. The purity is 99.9%. Yield: 35.6 g (60%).

Example 4

1st Step:

50 g (285 mmol) of 2-methyl indole-2-carboxylate, 47 g (143 mmol) of1,4-diiodobenzene and 98.5 g of K₂CO₃ (712.5 mmol) are suspended in 11of toluene. 15.8 g (114 mmol) of CuI and 10.06 g ofN,N′-dimethylenediamine (114 mmol) are added to this suspension. Thereaction mixture is heated under reflux for 48 h. After cooling, theprecipitate is filtered off via a fluted filter. The reaction solutionis subsequently partitioned between ethyl acetate and water, the organicphase is washed three times with water, dried over Na₂SO₄ and evaporatedin a rotary evaporator. The black-green oil remaining is filteredthrough silica gel with heptane:toluene. The evaporated filtrate residueis recrystallised from methanol. Yield: 48.5 g of1,4-di(1H-indole-2-methylcarboxylat-1-yl)benzene (80%).

2nd Step:

45 g (106 mmol) of 1,4-di-(1H-indole-2-methylcarboxylat-1-yl)benzene isinitially introduced in 500 ml of dimethylformamide. A solution of 37.5g (212 mmol) of NBS in 100 ml of dimethylformamide is subsequently addeddropwise at 0° C. with exclusion of light, the mixture is allowed tocome to RT and is stirred at this temperature for a further 4 h. Themixture is subsequently poured into ice-water. The precipitate isfiltered, washed with water and subsequently washed with heptane. Theproduct is washed by stirring with hot heptane and filtered off withsuction. Yield: 55.5 g (90%).

3rd Step:

30.9 g of anhydrous cerium(III) chloride (172 mmol) is initiallyintroduced in 700 ml of dry THF. 50 g (85.9 mmol) of1,4-di(1H-indole-3-bromo-2-methylcarboxylat-1-yl)benzene are meteredinto this solution in portions, and the mixture is stirred for 1 h. Thereaction mixture is cooled, and 200 ml (601 mmol) of methylmagnesiumchloride solution (3 mol/l in THF) are added dropwise over the course of40 min at 5° C. After one hour, the reaction mixture is carefully pouredonto ice and extracted three times with dichloromethane. The combinedorganic phases are dried over Na₂SO₄ and evaporated. The residue isrecrystallised from toluene. Yield: 47 g (95%).

4th Step:

26 g of polyphosphoric acid (270 mmol) and 25.9 g of methanesulfonicacid (270 mmol) are initially introduced in 500 ml of CH₂Cl₂. 45 g (77.3mmol) of the compound from step 3 in dichloromethane solution (150 ml)are added dropwise to this solution over the course of 30 min, and themixture is stirred at 50° C. for 1 h. After this time, the reactionmixture is cooled, carefully poured onto ice and extracted three timeswith dichloromethane. The combined organic phases are dried over Na₂SO₄and evaporated. The residue is recrystallised from toluene. Yield: 39.2g (90%).

5th Step:

35 g (62 mmol) of the compound from the 4th step, 15 g (124 mmol) ofphenylboronic acid and 124 ml of a 2M sodium carbonate solution aresuspended in 700 ml of ethylene glycol dimethyl ether. 3.58 g (3.1 mmol)of Pd(PPh₃)₄ are added to this suspension. The reaction mixture isheated under reflux for 5 h. After cooling, the precipitated solid isfiltered off with suction, washed with water and ethanol and dried. Theresidue is extracted with hot toluene, recrystallised from toluene andsubsequently sublimed in a high vacuum. The purity is 99.9%. Yield: 21.8g (65%).

B) Device Examples

OLEDs according to the invention are produced by a general process inaccordance with WO 2004/058911, which is adapted to the circumstancesdescribed here (layer-thickness variation, materials).

The data for various OLEDs are presented in Examples E1 to E9 below (seeTables 1 and 2). Glass plates coated with structured ITO (indium tinoxide) in a thickness of 150 nm are coated with 20 nm of PEDOT(poly(3,4-ethylenedioxy-2,5-thiophene), applied by spin coating fromwater; purchased from H. C. Starck, Goslar, Germany) for improvedprocessing. These coated glass plates form the substrates to which theOLEDs are applied. The OLEDs basically have the following layerstructure: substrate/optional hole-injection layer (HIL)/hole-transportlayer (HTL)/optional interlayer (IL)/electron-blocking layer(EBL)/emission layer (EML)/optional hole-blocking layer(HBL)/electron-transport layer (ETL)/optional electron-injection layer(EIL) and finally a cathode. The cathode is formed by an aluminium layerwith a thickness of 100 nm. The precise structure of the OLEDs is shownin Table 1. The materials required for the production of the OLEDs areshown in Table 3.

All materials are applied by thermal vapour deposition in a vacuumchamber. The emission layer here always consists of at least one matrixmaterial (host material) and an emitting dopant (emitter), to which thematrix material or materials is (are) admixed by co-evaporation in acertain proportion by volume. An expression such as IC1:3:TEG1(70%:20%:10%) here means that material IC1 is present in the layer in aproportion by volume of 70%, 3 is present in the layer in a proportionof 20% and TEG1 is present in the layer in a proportion of 10%.Analogously, the electrontransport layer may also consist of a mixtureof two materials.

The OLEDs are characterised by standard methods. For this purpose, theelectroluminescence spectra, the current efficiency (measured in cd/A),the power efficiency (measured in Im/W) and the external quantumefficiency (EQE, measured in percent) as a function of the luminousdensity, calculated from current/voltage/luminous density characteristiclines (IUL characteristic lines) assuming Lambert emissioncharacteristics) are determined. The electroluminescence spectra aredetermined at a luminous density of 1000 cd/m², and the CIE 1931× and ycolour coordinates are calculated therefrom. The expression U1000 inTable 2 denotes the voltage required for a luminous density of 1000cd/m². CE1000 and PE1000 denote the current and power efficiencyrespectively which are achieved at 1000 cd/m². Finally, EQE1000 denotesthe external quantum efficiency at an operating luminous density of 1000cd/m².

The data of the OLEDs are summarised in Table 2. Depending on thesubstitution pattern, the materials according to the invention can beemployed in different layers and functions. Good to very good values forefficiency and voltage can be achieved here.

According to a preferred embodiment, the compounds are used as matrixmaterials for red- and for green-phosphorescent emitters (CompoundExamples 1, 3 and 4). Device examples in this respect are E1-E4, E7 andE9. E1 and E2 here represent examples in which the compounds accordingto the invention are employed as the only matrix materials, and E3, E4,E7 and E9 represent examples in which the compounds according to theinvention are employed in combination with a further matrix material(mixed-matrix systems).

Furthermore, the compounds according to the invention can advantageouslybe employed as hole-transport materials, as shown with reference tocompound Example 2 in device Examples E5 and E6.

Again furthermore, the compounds according to the invention can beemployed as electron-transport materials, as shown with reference tocompound Example 1 in device Example E5.

TABLE 1 Structure of the OLEDs HIL HTL IL EBL EML HBL ETL EIL Ex.Thickness Thickness Thickness Thickness Thickness Thickness ThicknessThickness E1 — SpA1 — NPB 1:TER1 — Alq₃ LiF 20 nm 20 nm (85%:15%) 20 nm1 nm 30 nm E2 — SpA1 HATCN BPA1 1:TEG1 — ST2:LiQ — 70 nm 5 nm 90 nm(90%:10%) 30 nm (50%:50%) 40 nm E3 — SpA1 HATCN BPA1 ST1:3:TEG1 IC1ST2:LiQ — 70 nm 5 nm 90 nm (30%:60%:10%) 10 nm (50%:50%) 30 nm 30 nm E4— SpA1 HATCN BPA1 IC1:3:TEG1 — ST2:LiQ — 70 nm 5 nm 90 nm (30%:60%:10%)(50%:50%) 30 nm 40 nm E5 HATCN SpA1 — 2 M1:D1 — ST1:LiQ — 5 nm 140 nm 20nm (95%:5%) (50%:50%) 20 nm 30 nm E6 — SpA1 HATCN 2 IC1:TEG1 ST1 ST1:LiQ— 70 nm 5 nm 90 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm E7 — SpA1 — NPBST1:2:TER1 Alq₃ LiF 20 nm 20 nm (70%:15%:15%) 20 nm 1 nm 30 nm E8 — SpA1HATCN BPA1 ST1:TEG1 — 1 LiQ 70 nm 5 nm 90 nm (90%:10%) 40 nm 3 nm 30 nmE9 — SpA1 HATCN BPA1 IC1:4:TEG1 IC1 ST2:LiQ — 70 nm 5 nm 90 nm(70%:20%:10%) 10 nm (50%:50%) 30 nm 30 nm

TABLE 2 Data of the OLEDs U1000 CE1000 PE1000 EQE Ex. (V) (cd/A) (lm/W)1000 CIE x/y E1 4.7 7.7 5.1 12.8% 0.69/0.31 E2 3.7 51 43 14.1% 0.36/0.60E3 3.6 53 46 14.8% 0.36/0.60 E4 3.8 50 41 13.9% 0.36/0.60 E5 4.2 7.5 5.66.1% 0.14/0.15 E6 3.5 55 50 15.3% 0.36/0.60 E7 4.7 6.5 4.3 10.8%0.39/0.61 E8 4.3 48 35 13.2% 0.36/0.60 E9 3.5 56 50 15.6% 0.37/0.61

TABLE 3 Structural formulae of the materials for the OLEDs

HATCN

SpA1

NPB

BPA1

Alq₃

M1

D1

LiQ

ST1

ST2

TER1

TEG1

IC1

1

2

3

4

The invention claimed is:
 1. An electronic device, comprising an anode,a cathode and at least one organic layer, wherein the organic layercomprises at least one compound of the formula (I) or (II)

wherein: Y is C(R¹)₂; Z are on each occurrence, identically ordifferently, CR¹ or N; Q is CR¹; L is selected from C═O, C═NR¹, Si(R¹)₂,NR¹, P(═O)(R¹), O, S, SO, SO₂, alkylene groups having 1 to 20 C atoms oralkenylene or alkynylene groups having 2 to 20 C atoms, where one ormore CH₂ groups in the said groups may be replaced by Si(R¹)₂, O, S,C═O, C═NR¹, C(═O)O, (C═O)NR¹, NR¹, P(═O)(R¹), SO or SO₂ and where one ormore H atoms in the said groups may be replaced by D, F, Cl, Br, I, CNor NO₂, and aromatic or heteroaromatic ring systems having 5 to 60aromatic ring atoms, which may in each case be substituted by one ormore radicals R¹, and any desired combinations of 1, 2, 3, 4 or 5identical or different groups selected from the above-mentioned groups;or L is a single bond, where p in this case is equal to 2; R¹ is on eachoccurrence, identically or differently, H, D, F, Cl, Br, I, B(OR²)₂,CHO, C(═O)R², CR²═C(R²)₂, CN, C(═O)OR², C(═O)N(R²)₂, Si(R²)₃, N(R²)₂,NO₂, P(═O)(R²)₂, OSO₂R², OR², S(═O)R², S(═O)₂R², a straight-chain alkyl,alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclicalkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl oralkynyl group having 2 to 20 C atoms, where the above-mentioned groupsmay each be substituted by one or more radicals R² and where one or moreCH₂ groups in the above-mentioned groups may be replaced by —R²C═CR²—,—C≡C—, Si(R²)₂, Ge(R²)₂, Sn(R²)₂, C═O, C═S, C═Se, C═NR², —C(═O)O—,—C(═O)NR²—, NR², P(═O)(R²), —O—, —S—, SO or SO₂ and where one or more Hatoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I,CN or NO₂, or an aromatic or heteroaromatic ring system having 5 to 60aromatic ring atoms, which may in each case be substituted by one ormore radicals R², or an aryloxy, heteroaryloxy, aralkyl or heteroaralkylgroup having 5 to 60 aromatic ring atoms, which may be substituted byone or more radicals R²; R² is on each occurrence, identically ordifferently, H, D, F, Cl, Br, I, B(OR³)₂, CHO, C(═O)R³, CR³═C(R³)₂, CN,C(═O)OR³, C(═O)N(R³)₂, Si(R³)₃, N(R³)₂, NO₂, P(═O)(R³)₂, OSO₂R³, OR³,S(═O)R³, S(═O)₂R³, a straight-chain alkyl, alkoxy or thioalkyl grouphaving 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy orthioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl grouphaving 2 to 20 C atoms, where the above-mentioned groups may each besubstituted by one or more radicals R³ and where one or more CH₂ groupsin the above-mentioned groups may be replaced by —R³C═CR³—, —C≡C—,Si(R³)₂, Ge(R³)₂, Sn(R³)₂, C═O, C═S, C═Se, C═NR³, —C(═O)O—, —C(═O)NR³—,NR³, P(═O)(R³), —O—, —S—, SO or SO₂ and where one or more H atoms in theabove-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO₂, oran aromatic or heteroaromatic ring system having 5 to 60 aromatic ringatoms, which may in each case be substituted by one or more radicals R³,or an aryloxy, heteroaryloxy, aralkyl or heteroaralkyl group having 5 to60 aromatic ring atoms, which may be substituted by one or more radicalsR³, where two or more radicals R² may be linked to one another and mayform a ring or a ring system; R³ is on each occurrence, identically ordifferently, H, D, F or an aliphatic, aromatic and/or heteroaromaticorganic radical having 1 to 20 C atoms, in which, in addition, one ormore H atoms may be replaced by D or F; two or more substituents R³ heremay also be linked to one another and form a ring or a ring system; n ison each occurrence, identically or differently, 0 or 1, where, in thecase n=0, the group in brackets is not present and optionally groups R¹are instead bonded to the central benzene ring; p is equal to 2, 3, 4, 5or 6; and where the group Y and the nitrogen atom at any desiredadjacent positions may be bonded to the aromatic six-membered ring;where, in the formulae (I) and (II), in each case no or 1, 2 or 3 carbonatoms which are constituents of the central aromatic six-membered ringmay be replaced by N if the sum of the indices n is equal to 0, andwhere, in the formulae (I) and (II), in each case no or 1 or 2 carbonatoms which are constituents of the central aromatic six-membered ringmay be replaced by N if the sum of the indices n is equal to 1, andwhere, in formula (II), the moieties in square brackets with index pwhich are bonded to L may be identical or different; and where, informula (II), the group L may be bonded at any desired position of themoiety in square brackets with index p.
 2. The electronic deviceaccording to claim 1, wherein p is equal to
 2. 3. The electronic deviceaccording to claim 1, wherein the sum of the values for n in formula (I)and the sum of the values for n per unit in square brackets with index pin formula (II) is equal to
 0. 4. The electronic device according toclaim 1, wherein 0 or 1 group Z per aromatic ring is equal to N.
 5. Theelectronic device according to claim 1, wherein L is selected from asingle bond, where in this case p=2, or from C═O, NR¹, O or S, where inthese cases p=2, or from alkylene groups having 1 to 10 C atoms,alkenylene groups having 2 to 10 C atoms, where one or more CH₂ groupsin the said groups may be replaced by C═O, NR¹, P(═O)(R¹), O or S, andarylene or heteroarylene groups having 5 to 20 aromatic ring atoms,which may be substituted by one or more radicals R¹, or from divalentaromatic or heteroaromatic ring systems of the formula (L-1)*

E

_(i)

Ar¹

_(k)

E

_(i)

Ar¹

_(l)

E

_(i)*  formula (L-1), where p in this case is equal to 2 and wherein:Ar¹ is on each occurrence, identically or differently, an aryl orheteroaryl group having 5 to 20 aromatic ring atoms, which may in eachcase be substituted by one or more radicals R¹; E is on each occurrence,identically or differently, a single bond, C═O, NAr¹, P(═O)(R¹), O, S,SO or SO₂; i is on each occurrence, identically or differently, 0 or 1;k,l are on each occurrence, identically or differently, 0, 1, 2 or 3,where the sum of the values of k and 1 is greater than 0; and where thegroups Ar¹ may be connected to one another via one or more divalentgroups T, where T is selected on each occurrence, identically ordifferently, from a single bond, BR¹, C(R¹)₂, C═O, C═S, C═NR¹, C═C(R¹)₂,CR¹═CR¹, Si(R¹)₂, NR¹, PR¹, P(═O)R¹, O, S, S═O and S(═O)₂; and thesymbols * mark bonds from the group L to the remainder of the compound.6. The electronic device according to claim 1, wherein the compound ofthe formula (I) is selected from the formulae

where the compounds may be substituted by radicals R¹ at allunsubstituted positions.
 7. The electronic device according to claim 1,wherein the compound of the formula (II) is selected from the formulae

where the symbols occurring are as defined in claim 1 and the group Z towhich the group L is bonded stands for a carbon atom, and where thecompounds may be substituted by radicals R¹ at all unsubstitutedpositions.
 8. The electronic device according to claim 1, wherein thedevice is selected from the group consisting of an organic integratedcircuit, an organic field-effect transistor, an organic thin-filmtransistor, an organic light-emitting transistor, an organic solar cell,an organic optical detector, an organic photoreceptor, an organicfield-quench device, a light-emitting electrochemical cell, an organiclaser diode, and an organic electroluminescent device.
 9. The electronicdevice according to claim 1, wherein the device is an organicelectroluminescent device, wherein the compound of the formula (I) or(II) is present as hole-transport material in a hole-transport layer orhole-injection layer and/or is present as matrix material in an emittinglayer and/or is present as electron-transport material in anelectron-transport layer.
 10. A compound of the formula (I) or (II),

wherein: Y is C(R¹)₂; Z are on each occurrence, identically ordifferently, CR¹ or N; Q is CR¹; L is selected from C═O, C═NR¹, Si(R¹)₂,NR¹, P(═O)(R¹), O, S, SO, SO₂, alkylene groups having 1 to 20 C atoms oralkenylene or alkynylene groups having 2 to 20 C atoms, where one ormore CH₂ groups in the said groups may be replaced by Si(R¹)₂, O, S,C═O, C═NR¹, C(═O)O, (C═O)NR¹, NR¹, P(═O)(R¹), SO or SO₂ and where one ormore H atoms in the said groups may be replaced by D, F, Cl, Br, I, CNor NO₂, and aromatic or heteroaromatic ring systems having 5 to 60aromatic ring atoms, which may in each case be substituted by one ormore radicals R¹, and any desired combinations of 1, 2, 3, 4 or 5identical or different groups selected from the above-mentioned groups;or L is a single bond, where p in this case is equal to 2; R¹ is on eachoccurrence, identically or differently, H, D, F, Cl, Br, I, B(OR²)₂,CHO, C(═O)R², CR²═C(R²)₂, CN, C(═O)OR², C(═O)N(R²)₂, Si(R²)₃, N(R²)₂,NO₂, P(═O)(R²)₂, OSO₂R², OR², S(═O)R², S(═O)₂R², a straight-chain alkyl,alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclicalkyl, alkoxy or thioalkyl group having 3 to 20 C atoms or an alkenyl oralkynyl group having 2 to 20 C atoms, where the above-mentioned groupsmay each be substituted by one or more radicals R² and where one or moreCH₂ groups in the above-mentioned groups may be replaced by —R²C═CR²—,—C≡C—, Si(R²)₂, Ge(R²)₂, Sn(R²)₂, C═O, C═S, C═Se, C═NR², —C(═O)O—,—C(═O)NR²—, NR², P(═O)(R²), —O—, —S—, SO or SO₂ and where one or more Hatoms in the above-mentioned groups may be replaced by D, F, Cl, Br, I,CN or NO₂, or an aromatic or heteroaromatic ring system having 5 to 60aromatic ring atoms, which may in each case be substituted by one ormore radicals R², or an aryloxy, heteroaryloxy, aralkyl or heteroaralkylgroup having 5 to 60 aromatic ring atoms, which may be substituted byone or more radicals R²; R² is on each occurrence, identically ordifferently, H, D, F, Cl, Br, I, B(OR³)₂, CHO, C(═O)R³, CR³═C(R³)₂, CN,C(═O)OR³, C(═O)N(R³)₂, Si(R³)₃, N(R³)₂, NO₂, P(═O)(R³)₂, OSO₂R³, OR³,S(═O)R³, S(═O)₂R³, a straight-chain alkyl, alkoxy or thioalkyl grouphaving 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy orthioalkyl group having 3 to 20 C atoms or an alkenyl or alkynyl grouphaving 2 to 20 C atoms, where the above-mentioned groups may each besubstituted by one or more radicals R³ and where one or more CH₂ groupsin the above-mentioned groups may be replaced by —R³C═CR³—, —C≡C—,Si(R³)₂, Ge(R³)₂, Sn(R³)₂, C═O, C═S, C═Se, C═NR³, —C(═O)O—, —C(═O)NR³—,NR³, P(═O)(R³), —O—, —S—, SO or SO₂ and where one or more H atoms in theabove-mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO₂, oran aromatic or heteroaromatic ring system having 5 to 60 aromatic ringatoms, which may in each case be substituted by one or more radicals R³,or an aryloxy, heteroaryloxy, aralkyl or heteroaralkyl group having 5 to60 aromatic ring atoms, which may be substituted by one or more radicalsR³, where two or more radicals R² may be linked to one another and mayform a ring or a ring system; R³ is on each occurrence, identically ordifferently, H, D, F or an aliphatic, aromatic and/or heteroaromaticorganic radical having 1 to 20 C atoms, in which, in addition, one ormore H atoms may be replaced by D or F; two or more substituents R³ heremay also be linked to one another and form a ring or a ring system; n ison each occurrence, identically or differently, 0 or 1, where, in thecase n=0, the group in brackets is not present and optionally groups R¹are instead bonded to the central benzene ring; p is equal to 2, 3, 4, 5or 6; and where the group Y and the nitrogen atom at any desiredadjacent positions may be bonded to the aromatic six-membered ring;where, in the formulae (I) and (II), in each case no or 1, 2 or 3 carbonatoms which are constituents of the central aromatic six-membered ringmay be replaced by N if the sum of the indices n is equal to 0, andwhere, in the formulae (I) and (II), in each case no or 1 or 2 carbonatoms which are constituents of the central aromatic six-membered ringmay be replaced by N if the sum of the indices n is equal to 1, andwhere, in formula (II), the moieties in square brackets with index pwhich are bonded to L may be identical or different; and where, informula (II), the group L may be bonded at any desired position of themoiety in square brackets with index p; and the following compounds areexcluded:


11. An oligomer, a polymer or a dendrimer comprising one or morecompound according to claim 10, wherein one or more bond to the polymer,the oligomer or the dendrimer may be localised at any positions informula (I) or (II) that are substituted by R⁰ or R¹.
 12. A formulationcomprising at least one compound according to claim 10 and at least onesolvent.
 13. A formulation comprising at least one polymer, oligomer ordendrimer according to claim 11 and at least one solvent.